JPH0635868U - Refrigeration circuit with intermediate injection circuit - Google Patents

Abstract

(57) [Abstract] [Purpose] In a refrigeration circuit with an intermediate injection circuit, an excessively subcooled refrigerant is prevented from being supplied from a condenser to an expansion mechanism in the intermediate injection circuit, whereby an intermediate injection circuit is provided. Prevent the pulsation of. [Structure] An inlet 1 of an intermediate injection circuit 9 having a main circuit 10 in which a compressor 1, a condenser 3, a main expansion mechanism 4, and an evaporator 5 are sequentially connected by piping, and further having an expansion mechanism 12.
1 is connected to a main circuit portion between the condenser 3 and the main expansion mechanism 9 via a branching device 7, and a refrigerant reservoir 16 is provided in a main circuit portion between the branching device 7 and the condenser 3. A refrigeration circuit with an intermediate injection circuit provided with a pulsation prevention circuit section 15.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a refrigeration circuit having an intermediate injection circuit.

[0002]

[Prior art]

 Conventionally, CFCs such as CFC R502 have been used as refrigerants in refrigeration circuits used in environmental testers, etc., but in recent years, CFCs such as CFC R22, etc. have been used as alternatives because these types of refrigerants may cause environmental damage. Is being changed to a refrigerant. However, due to the characteristics of the alternative refrigerant such as CFC R22, when adiabatically compressed by the compressor in the refrigeration circuit, the refrigerant temperature at the compressor discharge portion tends to rise, which causes deterioration of the refrigerant and deterioration of the compressor oil. In order to prevent such a problem, an intermediate injection circuit is provided.

The intermediate injection circuit is provided with an expansion mechanism, the inlet of which is connected via a branching device to the portion of the refrigeration circuit between the condenser and the expansion mechanism of the main circuit, and the outlet of which is the intermediate of the compressor. It is connected to the injection port. With such an intermediate injection circuit, a part of the refrigerant condensed in the condenser can be returned to the compressor without passing through the expansion mechanism and the evaporator of the main circuit, so that the compressor is cooled, The abnormal temperature rise can be prevented.

[0004]

[Problems to be solved by the device]

 However, in the conventional refrigeration circuit including the intermediate injection circuit, the lower limit of the subcooling degree of the condensed liquid refrigerant is set, but the upper limit of the subcooling degree is not limited. Therefore, the liquid refrigerant may be excessively cooled in the condenser, and in that case, the refrigerant expanded by the expansion mechanism in the intermediate injection circuit does not become a gas-liquid two-phase state, but only a liquid phase. It becomes a state. As a result, the pulsation of the refrigerant flowing through the intermediate injection circuit may occur, and the vibration may damage the intermediate injection circuit.

It is an object of the present invention to provide a refrigeration circuit with an intermediate injection circuit that solves the above problems.

[0006]

[Means for Solving the Problems]

 According to the above-mentioned object, the present invention has a main circuit in which a compressor, a condenser, a main expansion mechanism and an evaporator are sequentially connected by piping, and further, an inlet of an intermediate injection circuit equipped with an expansion mechanism is provided at the condenser and the main expansion mechanism. And a main circuit part between the branching device and the condenser by connecting the outlet of the intermediate injection circuit to the intermediate injection port of the compressor through a branching device. In addition, the present invention provides a chilling circuit with an intermediate injection circuit, characterized in that a pulsation prevention circuit section having a refrigerant reservoir is provided.

As the branch device, a three-way pipe, a liquid receiver, or the like is used.

[0008]

[Action]

 According to the refrigeration circuit of the present invention, the refrigerant that has flowed into the condenser does not accumulate there for a long time, immediately flows out of the condenser and flows into the refrigerant reservoir of the pulsation prevention circuit section, and from there, through the branch device, the main expansion mechanism and It flows into the intermediate injection circuit. Therefore, the refrigerant is not excessively supercooled in the condenser, the excessively supercooled refrigerant is prevented from flowing to the expansion mechanism in the intermediate injection circuit, and is expanded by the expansion mechanism. The refrigerant is in a gas-liquid two-phase state. As a result, no pulsation occurs in the refrigerant flowing through the intermediate injection circuit.

[0009]

【Example】

 Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows one embodiment. In FIG. 1, a compressor 1, a condenser 3, a main expansion valve 4, and an evaporator 5 are connected in series to a main circuit 10 of the refrigeration circuit by piping. The flow direction of the refrigerant in the main circuit 10 is indicated by a solid arrow.

A branching device 7 is provided in the main circuit portion between the condenser 3 and the main expansion valve 4, and the inlet 11 of the intermediate injection circuit 9 is connected to the main circuit portion via the branching device 7. ing. The branching device 7 is a three-way pipe (cheese) in this example. The intermediate injection circuit 9 is provided with an expansion mechanism 12 (capillary tube in this example) on the way, and its outlet is connected to the intermediate injection port 13 of the compressor 1.

Further, a pulsation prevention circuit section 15 is provided between the condenser 3 and the branching device 7 of the main circuit 10. The pulsation prevention circuit section 15 is formed of, for example, a tank, and includes a refrigerant reservoir 16. Thus, the refrigerant reservoir 16 added downstream of the condenser 3 increases the pipe capacity. Therefore, the portion related to supercooling of the condenser 3 can be set small correspondingly.

According to the structure described above, the refrigerant is condensed in the condenser 3, and the refrigerant promptly discharged therefrom is temporarily accumulated in the refrigerant reservoir 16 and is then transferred to the expansion valve 4 and the intermediate injection circuit 9. Sent. Therefore, the excessively subcooled refrigerant does not flow to the expansion mechanism 12 of the intermediate injection circuit 9, and the refrigerant expanded by the expansion mechanism 12 becomes a gas-liquid two-phase state. As a result, pulsation does not occur in the refrigerant flowing through the intermediate injection circuit 9. Therefore, there is no possibility that the circuit 9 will be damaged due to pulsation.

[0013]

[Effect of device]

 As described above, according to the refrigeration circuit with the intermediate injection circuit of the present invention, since the refrigerant reservoir is added to the condenser to prevent excessive supercooling in the condenser, the pulsation of the refrigerant in the intermediate injection circuit is prevented, This has the advantage of preventing damage to the intermediate injection circuit.

[Brief description of drawings]

FIG. 1 is a circuit diagram of a refrigeration circuit according to an embodiment of the present invention.

[Explanation of reference numerals] 1 compressor 3 condenser 4 main expansion valve 5 evaporator 7 branching device 9 intermediate injection circuit 10 main circuit 11 inlet 12 expansion mechanism 13 intermediate injection port 15 pulsation prevention circuit section 16 refrigerant reservoir

Claims (1)

[Scope of utility model registration request] 1. A main circuit in which a compressor, a condenser, a main expansion mechanism and an evaporator are sequentially connected by pipes, and an inlet of an intermediate injection circuit equipped with an expansion mechanism is provided between the condenser and the main expansion mechanism. The main circuit portion between the branch device and the condenser, the outlet of the intermediate injection circuit is connected to the intermediate injection port of the compressor while connecting to the main circuit portion between A refrigeration circuit with an intermediate injection circuit, characterized in that a pulsation prevention circuit section having the above is provided.